<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    // 1- 实例属性当中没有，会去原型中找
    // 2- 原型对象是共享的
    function Box(){
        this.a = 1;
		this.b = 2;
    }
	Box.prototype.arr = [1,2,3,4]
	const obj = new Box();
	const obj2 = new Box();
	// console.log(obj.__proto__===obj2.__proto__);
    obj2.arr.push(100)
	console.log(obj.arr,obj2.arr)
</script>
</html>